A magnitude-3.8 earthquake struck
at 9:08 a.m. about 8 miles northeast of Borrego Springs and 20.9 miles
south of La Quinta, according to the U.S. Geological Survey.
A small rattle was felt in the Coachella Valley, including in Indio on Day 2 of the Coachella Valley Music and Arts festival.
Location: Really deep in the heart of South California Gender:
Posted:
Apr 14, 2024 - 8:51am
An article in today's newspaper...
A magnitude-3.8 earthquake struck
at 9:08 a.m. about 8 miles northeast of Borrego Springs and 20.9 miles
south of La Quinta, according to the U.S. Geological Survey.
A small rattle was felt in the Coachella Valley, including in Indio on Day 2 of the Coachella Valley Music and Arts festival.
Now, with this ~ M4 aftershock the aftershock forecast has changed over the next week. You now have a 16% chance of an M4 ( but less than 1-2 % chance of an M5) and a 76% chance of an M3-3.9. So, youâll likely feel another shake but they SHOULD all be lower than the M4.8 main shock.
Thereâs a lot of science regarding aftershocks, they decay almost exponentially in most earthquakes, so, for this size earthquake they should be done within a week. Larger earthquakes have longer aftershock periods. M7+ earthquakes can have aftershocks for months. Iâve been in some large earthquakes and have been studying some very large ones right after they occur. The aftershocks for those can be large, M5 -6. Those make me jumpy.
So we could have earthquake aftershocks during a solar eclipse. Awesome. Are there any signs of tsunami activity?
Now, with this ~ M4 aftershock the aftershock forecast has changed over the next week. You now have a 16% chance of an M4 ( but less than 1-2 % chance of an M5) and a 76% chance of an M3-3.9. So, youâll likely feel another shake but they SHOULD all be lower than the M4.8 main shock.
Thereâs a lot of science regarding aftershocks, they decay almost exponentially in most earthquakes, so, for this size earthquake they should be done within a week. Larger earthquakes have longer aftershock periods. M7+ earthquakes can have aftershocks for months. Iâve been in some large earthquakes and have been studying some very large ones right after they occur. The aftershocks for those can be large, M5 -6. Those make me jumpy.
no alerts. just the low rumbles like a big truck was going by.
they're reporting this the biggest quake on record in Philly area. although the one in 2011 (centered in Virginia) shook us a lot more. I saw the frickin' wall and floor waving.
I was at work when that one hit. In a mobile trailer type thingy, and was standing in the hall outside my office talking to a co-worker when I notice my snake plant swaying. I said: "I think that was an earthquake." He hadn't even noticed. When I got home (closer to the epicenter than work), Middy (remember Middy?) was beside herself. As if to say: "I didn't do it, Mom!" Nothing off the walls, but all the pictures were askew and some things were knocked over.
Iâm always a little leery that someoneâs posting a video from another earthquake but the accents give me confidence this is NJ. Note the little dog reacts to the bang and jolt. Thatâs the p-wave. Then the big shaking comes in, thatâs the shear wave (s-wave). There are other waves that follow. The second part of the video, shot down the hall is great as well, can really see the pop of the p-wave. Also, the duration of the earthquake, I count about 5-6 seconds is what we expect from that size event. https://x.com/rawsalerts/statu...
lol they just showed that video on the news.
we're about 60 miles from the center. wasn't that shook. felt more like the floor vibrating.
there was a 2.2 in the same area last week. pre-shock they are saying
no alerts. just the low rumbles like a big truck was going by.
they're reporting this the biggest quake on record in Philly area. although the one in 2011 (centered in Virginia) shook us a lot more. I saw the frickin' wall and floor waving.
Iâm always a little leery that someoneâs posting a video from another earthquake but the accents give me confidence this is NJ. Note the little dog reacts to the bang and jolt. Thatâs the p-wave. Then the big shaking comes in, thatâs the shear wave (s-wave). There are other waves that follow. The second part of the video, shot down the hall is great as well, can really see the pop of the p-wave. Also, the duration of the earthquake, I count about 5-6 seconds is what we expect from that size event. https://x.com/rawsalerts/statu...
If you werenât already aware, there is an event page the USGS develops (usually within 5 min of the earthquake). It is here https://earthquake.usgs.gov/ea...
A couple of notable things 1) within that event page is a âDid you feel it?â Inquiry https://earthquake.usgs.gov/ea.... This provides incredible intensity information to develop site attenuation models and such - please consider putting your info in it. 2) there have been over 109, 000 responses thus far! That amazing for a M4.8 event however, 3 things factor in a) lots of people available to experience event, b) shallow (less than 4 km deep (most western eqâs are 10 -15 km or greater and c) your rocks are old, strong and unbroken (like a good bell. The responses are more than 100 miles from the epicenter, Iâll bet people will report it over 200 miles away. That doesnât happen in the west, our bell is not as strong. 3) Most New England earthquakes are caused by glacial rebound (not tectonics). You had kmâs of ice sitting on the crust about 20 - 12 thousand years ago. Thatâs lots of weight. It depressed the crust. The ice suddenly melted (over a few thousand years) and the crust is still âbouncing back.â If you put a significant weight on rocks for a long period of time they will flex (elastically), if you remove that weight quickly they may respond in a brittle way (hence earthquake). 4) one other thing to note - the USGS provides a forecast of potential aftershocks over the next week - in your case you have a 16% chance of having a M4+ and a 46% chance of an M3+ It is very unlikely, but not impossible, that you will feel another the same size or greater.https://earthquake.usgs.gov/ea...
There will be a lot of info to come.
I was at USGA site before they even posted. LOL
I'll post my info there when I get home.
Jrzy, did something alert you to the beginning of the shaking, like a banging sound, a pop or a jolt? The low rumble was likely the shear wave (accompanied by swaying motion). The sudden motion would be the primary (p wave). In smaller earthquakes most people donât realize thatâs what alerted them to the beginning of the event
no alerts. just the low rumbles like a big truck was going by.
they're reporting this the biggest quake on record in Philly area. although the one in 2011 (centered in Virginia) shook us a lot more. I saw the frickin' wall and floor waving.
Location: Perched on the precipice of the cauldron of truth
Posted:
Apr 5, 2024 - 10:19am
geoff_morphini wrote:
If you werenât already aware, there is an event page the USGS develops (usually within 5 min of the earthquake). It is here https://earthquake.usgs.gov/ea...
A couple of notable things 1) within that event page is a âDid you feel it?â Inquiry https://earthquake.usgs.gov/ea.... This provides incredible intensity information to develop site attenuation models and such - please consider putting your info in it. 2) there have been over 109, 000 responses thus far! That amazing for a M4.8 event however, 3 things factor in a) lots of people available to experience event, b) shallow (less than 4 km deep (most western eqâs are 10 -15 km or greater and c) your rocks are old, strong and unbroken (like a good bell. The responses are more than 100 miles from the epicenter, Iâll bet people will report it over 200 miles away. That doesnât happen in the west, our bell is not as strong. 3) Most New England earthquakes are caused by glacial rebound (not tectonics). You had kmâs of ice sitting on the crust about 20 - 12 thousand years ago. Thatâs lots of weight. It depressed the crust. The ice suddenly melted (over a few thousand years) and the crust is still âbouncing back.â If you put a significant weight on rocks for a long period of time they will flex (elastically), if you remove that weight quickly they may respond in a brittle way (hence earthquake). 4) one other thing to note - the USGS provides a forecast of potential aftershocks over the next week - in your case you have a 16% chance of having a M4+ and a 46% chance of an M3+ It is very unlikely, but not impossible, that you will feel another the same size or greater.https://earthquake.usgs.gov/ea...
Jrzy, did something alert you to the beginning of the shaking, like a banging sound, a pop or a jolt? The low rumble was likely the shear wave (accompanied by swaying motion). The sudden motion would be the primary (p wave). In smaller earthquakes most people donât realize thatâs what alerted them to the beginning of the event
Jrzy and I live pretty close to each other...and I heard it...a loud rumble...and then the platter of my turntable started banging into the "walls" of the deck behind me. Given the rain, and the fact that a tree came down in the woods by my house, I was worried that one of the larger trees had fallen on my house.
